CVE-2017-2624

high

Description

It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.

References

http://www.securityfocus.com/bid/96480

http://www.securitytracker.com/id/1037919

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624

https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a18627c

https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html

https://security.gentoo.org/glsa/201704-03

https://security.gentoo.org/glsa/201710-30

https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/

Details

Source: MITRE

Published: 2018-07-27

Updated: 2019-10-09

Type: CWE-200

Risk Information

CVSS v2

Base Score: 1.9

Vector: AV:L/AC:M/Au:N/C:P/I:N/A:N

Impact Score: 2.9

Exploitability Score: 3.4

Severity: LOW

CVSS v3

Base Score: 7

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 1

Severity: HIGH